Global Simulations of Wave/Particle Interactions in the Radiation Belts

Abstract:

Global MHD models of the Sun-Earth interaction may be combined with test particle simulations of the radiation belts to examine important dynamical effects describable within the MHD approximation. Such effects include magnetopause shadowing, radial diffusion, convection, and substorm injections. However, important non-MHD processes, such as local energization and pitch angle scattering through interaction with high frequency (kHz) plasma waves, cannot be captured through MHD/particle simulations alone. In this work we introduce a comprehensive simulation framework that combines global MHD/test particle techniques with a Stochastic Differential Equation (SDE) method for addressing high frequency wave-particle interactions in a global framework. We examine the March 17, 2013 storm-time acceleration period, an NSF-GEM focus challenge event, to quantify the relative importance of physical processes such as magnetopause shadowing, diffusive and advective transport processes, and wave-particle interactions through the various phases of the storm.